mpeg2enc
This element encodes raw video into an MPEG-1/2 elementary stream using the mjpegtools library.
Documentation on MPEG encoding in general can be found in the MJPEG Howto and on the various available parameters in the documentation of the mpeg2enc tool in particular, which shares options with this element.
Example pipeline
gst-launch-1.0 videotestsrc num-buffers=1000 ! mpeg2enc ! filesink location=videotestsrc.m1v
This example pipeline will encode a test video source to a an MPEG1 elementary stream (with Generic MPEG1 profile).
Likely, the format property is most important, as it selects the type of MPEG stream that is produced. In particular, default property values are dependent on the format, and can even be forcibly restrained to certain pre-sets (and thereby ignored). Note that the (S)VCD profiles also restrict the image size, so some scaling may be needed to accommodate this. The so-called generic profiles (as used in the example above) allow most parameters to be adjusted.
gst-launch-1.0 videotestsrc num-buffers=1000 ! videoscale ! mpeg2enc format=1 norm=p ! filesink location=videotestsrc.m1v
This will produce an MPEG1 profile stream according to VCD2.0 specifications for PAL norm (as the image height is dependent on video norm).
Hierarchy
GObject ╰──GInitiallyUnowned ╰──GstObject ╰──GstElement ╰──GstVideoEncoder ╰──mpeg2enc
Implemented interfaces
Factory details
Authors: – Andrew Stevens
Classification: – Codec/Encoder/Video
Rank – marginal
Plugin – mpeg2enc
Package – GStreamer Bad Plug-ins
Pad Templates
sink
video/x-raw:
format: I420
width: [ 16, 4096 ]
height: [ 16, 4096 ]
framerate: { (fraction)24000/1001, (fraction)24/1, (fraction)25/1, (fraction)30000/1001, (fraction)30/1, (fraction)50/1, (fraction)60000/1001 }
src
video/mpeg:
systemstream: false
mpegversion: { (int)1, (int)2 }
width: [ 16, 4096 ]
height: [ 16, 4096 ]
framerate: { (fraction)24000/1001, (fraction)24/1, (fraction)25/1, (fraction)30000/1001, (fraction)30/1, (fraction)50/1, (fraction)60000/1001 }
Properties
altscan-mpeg2
“altscan-mpeg2” gboolean
Alternate MPEG-2 block scanning. Disabling this might make buggy players play SVCD streams
Flags : Read / Write
Default value : true
b-per-refframe
“b-per-refframe” gint
Number of B frames between each I/P frame
Flags : Read / Write
Default value : 0
bufsize
“bufsize” gint
Target decoders video buffer size (kB) (default depends on format)
Flags : Read / Write
Default value : 0
closed-gop
“closed-gop” gboolean
All Group-of-Pictures are closed (for multi-angle DVDs)
Flags : Read / Write
Default value : false
constraints
“constraints” gboolean
Use strict video resolution and bitrate checks
Flags : Read / Write
Default value : true
correct-svcd-hds
“correct-svcd-hds” gboolean
Force SVCD width to 480 instead of 540/720
Flags : Read / Write
Default value : false
disable-encode-retries
“disable-encode-retries” gboolean
Prevent the encoder from reencoding pictures in a second pass.
This can vastly improve performance, but potentially affect reaching bitrate targets.
See https://sourceforge.net/p/mjpeg/bugs/141/ for some background.
Flags : Read / Write
Default value : false
Since : 1.18
dualprime
“dualprime” gboolean
Dual Prime Motion Estimation Mode for MPEG-2 I/P-frame only streams. Quite some players do not support this.
Flags : Read / Write
Default value : false
dummy-svcd-sof
“dummy-svcd-sof” gboolean
Generate dummy SVCD scan-data (for vcdimager)
Flags : Read / Write
Default value : true
force-b-b-p
“force-b-b-p” gboolean
Force two B frames between I/P frames when closing GOP boundaries
Flags : Read / Write
Default value : false
format
“format” GstMpeg2encFormat *
Encoding profile format
Flags : Read / Write
Default value : 0 (0)
framerate
“framerate” GstMpeg2encFramerate *
Output framerate
Flags : Read / Write
Default value : 0 (0)
interlace-mode
“interlace-mode” GstMpeg2encInterlaceMode *
MPEG-2 motion estimation and encoding modes
Flags : Read / Write
Default value : -1 (-1)
intra-dc-prec
“intra-dc-prec” gint
Number of bits precision for DC (base colour) in MPEG-2 blocks
Flags : Read / Write
Default value : 9
keep-hf
“keep-hf” gboolean
Maximize high-frequency resolution (for high-quality sources)
Flags : Read / Write
Default value : false
max-gop-size
“max-gop-size” gint
Maximal size per Group-of-Pictures (-1=default)
Flags : Read / Write
Default value : -1
min-gop-size
“min-gop-size” gint
Minimal size per Group-of-Pictures (-1=default)
Flags : Read / Write
Default value : -1
motion-search-radius
“motion-search-radius” gint
Motion compensation search radius
Flags : Read / Write
Default value : 0
non-video-bitrate
“non-video-bitrate” gint
Assumed bitrate of non-video for sequence splitting (kbps)
Flags : Read / Write
Default value : 0
norm
“norm” GstMpeg2encVideoNorm *
Tag output for specific video norm
Flags : Read / Write
Default value : 0 (0)
playback-field-order
“playback-field-order” GstMpeg2encPlaybackFieldOrders *
Force specific playback field order
Flags : Read / Write
Default value : 0 (-1)
pulldown-3-2
“pulldown-3-2” gboolean
Generate header flags for 3-2 pull down 24fps movies
Flags : Read / Write
Default value : false
quant-matrix
“quant-matrix” GstMpeg2encQuantisationMatrix *
Quantisation matrix to use for encoding
Flags : Read / Write
Default value : 9 (0)
quant-reduction-max-var
“quant-reduction-max-var” gfloat
Maximal luma variance below which quantisation boost is used
Flags : Read / Write
Default value : 100
quantisation
“quantisation” gint
Quantisation factor (-1=cbr, 0=default, 1=best, 31=worst)
Flags : Read / Write
Default value : 0
quantisation-reduction
“quantisation-reduction” gfloat
Max. quantisation reduction for highly active blocks
Flags : Read / Write
Default value : 0
reduce-hf
“reduce-hf” gfloat
How much to reduce high-frequency resolution (by increasing quantisation)
Flags : Read / Write
Default value : 0
reduction-2x2
“reduction-2x2” gint
Reduction factor for 2x2 subsampled candidate motion estimates (1=max. quality, 4=max. speed)
Flags : Read / Write
Default value : 3
reduction-4x4
“reduction-4x4” gint
Reduction factor for 4x4 subsampled candidate motion estimates (1=max. quality, 4=max. speed)
Flags : Read / Write
Default value : 2
sequence-header-every-gop
“sequence-header-every-gop” gboolean
Include a sequence header in every GOP
Flags : Read / Write
Default value : false
sequence-length
“sequence-length” gint
Place a sequence boundary after each
Flags : Read / Write
Default value : 0
unit-coeff-elim
“unit-coeff-elim” gint
How aggressively small-unit picture blocks should be skipped
Flags : Read / Write
Default value : 0
vcd-still-size
“vcd-still-size” gint
Size of VCD stills (in KB)
Flags : Read / Write
Default value : 0
Named constants
GstMpeg2encAspect
Members
0 (0) – Deduce from input
1 (1) – 1:1
2 (2) – 4:3
3 (3) – 16:9
4 (4) – 2.21:1
GstMpeg2encFormat
Members
0 (0) – Generic MPEG-1
1 (1) – Standard VCD
2 (2) – User VCD
3 (3) – Generic MPEG-2
4 (4) – Standard SVCD
5 (5) – User SVCD
6 (6) – VCD Stills sequences
7 (7) – SVCD Stills sequences
8 (8) – DVD MPEG-2 for dvdauthor
9 (9) – DVD MPEG-2
10 (10) – ATSC 480i
11 (11) – ATSC 480p
12 (12) – ATSC 720p
13 (13) – ATSC 1080i
GstMpeg2encFramerate
Members
0 (0) – Same as input
1 (1) – 24/1.001 (NTSC 3:2 pulldown converted film)
2 (2) – 24 (native film)
3 (3) – 25 (PAL/SECAM video)
4 (4) – 30/1.001 (NTSC video)
5 (5) – 30
6 (6) – 50 (PAL/SECAM fields)
7 (7) – 60/1.001 (NTSC fields)
8 (8) – 60
GstMpeg2encInterlaceMode
Members
-1 (-1) – Format default mode
0 (0) – Progressive
1 (1) – Interlaced, per-frame encoding
2 (2) – Interlaced, per-field-encoding
GstMpeg2encPlaybackFieldOrders
Members
0 (-1) – Unspecified
1 (1) – Top-field first
2 (2) – Bottom-field first
GstMpeg2encQuantisationMatrix
Members
9 (0) – Default
1 (1) – High resolution
2 (2) – KVCD
3 (3) – TMPGEnc
GstMpeg2encVideoNorm
Members
0 (0) – Unspecified
p (112) – PAL
n (110) – NTSC
s (115) – SECAM
The results of the search are